Question

Which compound is formed when calcium carbide reacts with heavy water?
A) \[{C_2}{D_2}\]
B) \[Ca{D_2}\]
C) \[C{D_2}\]
D) \[C{a_2}{D_2}\]

Answer 1

Hint: Try to recall that the reaction of calcium carbide with water is a double displacement reaction and also, it is a hydrolysis reaction. Now, by using this you can easily find the correct option from the given ones.

Complete step by step solution:
It is known to you that when normal water reacts with calcium carbide it produces acetylene gas and calcium hydroxide. The chemical formula of calcium carbide is \[Ca{C_2}\] and its reaction with normal water (\[{H_2}O\]) is as follows:
\[Ca{C_2} + {H_2}O \to Ca{\left( {OH} \right)_2} + {C_2}{H_2}\].
The chemical formula of heavy water is \[{D_2}O\] and it is not very different from normal water in most of its chemical properties.
Heavy water has slightly higher values of physical constants because of its higher molecular mass as compared to that of ordinary water.
 It reacts very much similar to normal water with calcium carbide. In hydrolysis, one compound is broken down into two different compounds by reaction with heavy water.
The reaction of calcium carbide with heavy water is as follows:
\[Ca{C_2} + {D_2}O \to Ca{\left( {OD} \right)_2} + {C_2}{D_2}\]. Here, the D from D-OD goes to carbon to form \[{C_2}{D_2}\] and the remaining OD part goes to calcium to form \[Ca{\left( {OD} \right)_2}\]. Thus, hydrolysis of calcium carbide with heavy water is a type of double displacement reaction.

Therefore, from above we can conclude that option A is the correct option for the given question.

Note: It should be remembered to you that calcium carbide is used as a chemical ripening agent for fruits and it is the main source of acetylene.
Also, you should remember that a large amount of carbide is also used for the production of calcium cyanamide by the fixation of atmospheric nitrogen.